Cricket is a game where having a time restriction is not good at all. Cause if you restrict the fielding team with time the bowlers are not going to be able to perform well. Because a bowler needs a little bit of time to get ready for the next ball. Especially if he is a fast bowler. Nowadays, I have seen some bowlers, even run back to his mark as soon as he balls his ball. That is definitely not good. But with everything, getting faster and faster, and ICC giving every benefit to the batsmen, this was definitely going to happen. That is also a reason why many teams want to have three spinners in the team. They can move on with the overs quickly. There was a time when the top teams had four fast bowlers in the team. Those days are now past.
I am not sure what can be done for the time restriction. ICC introduced the rule, as the media rights holders were complaining about matches getting delayed and overshooting the allocated timeframe. And obviously when the duration is being considered, the pace bowlers are going to get more when compared to the spinners. And this means that when it comes to selection, the spin bowlers are sometimes selected ahead of pacers, just because they will help the captain to finish overs within the allocated time.